Metal-insulator-metal capacitor within metallization structure

ABSTRACT

A metallization structure of an integrated circuit (IC) includes: an intermetal dielectric (IMD) layer; a patterned metal layer embedded in the IMD layer; a patterned top metal layer disposed on the IMD layer; electrical vias comprising via material passing through the IMD layer and connecting the patterned top metal layer and the patterned metal layer embedded in the IMD layer; and a metal-insulator-metal (MIM) capacitor. The MIM capacitor includes: a first capacitor metal layer comprising the via material contacting an MIM capacitor landing area of the patterned metal layer embedded in the IMD layer; a second capacitor metal layer comprising the via material contacting a first MIM capacitor terminal area of the patterned top metal layer; and an insulator layer disposed between the first capacitor metal layer and the second capacitor metal layer.

BACKGROUND

The following relates to integrated circuit (IC) arts, back end of line(BEOL) fabrication arts, and to related arts.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 diagrammatically illustrates a cross-sectional view of anintegrated circuit (IC) including a metallization structure with acontact and a MIM capacitor according to an embodiment.

FIG. 2 diagrammatically illustrates a cross-sectional isolation view ofthe MIM capacitor of the metallization structure of FIG. 1 .

FIG. 3 diagrammatically illustrates a at least a portion of a backend-of-line (BEOL) fabrication process including fabrication of acontact pad and a BEOL MIM capacitor according to an embodiment.

FIGS. 4-14 diagrammatically show cross-sectional views of the BEOLmetallization structure under fabrication at various steps of the BEOLfabrication process of FIG. 3 .

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

An integrated circuit (IC) fabrication process is sometimes divided intofront end-of-line (FEOL) and back end-of-line (BEOL) stages. The FEOLstage entails fabrication of transistors, charge storage devices, andother circuit components. The BEOL stage entails fabrication of ametallization structure that interconnects the various circuitcomponents to form the complex circuitry of the IC. The metallizationstructure typically includes an intermetal dielectric (IMD) layer withone or more patterned metal layers embedded in the IMD layer, and a toppatterned metal layer disposed on the IMD layer. Each metal layer ispatterned in a specific pattern that defines electrical paths or traces,and these paths or traces of the metal layers collectively provide theelectrical interconnections of the circuit components of the IC to formthe IC circuitry. Such electrical paths or traces connections may bedirect or indirect (e.g. an upper metal layer may be patterned to definetraces connecting areas of a lower buried patterned metal layer).Electrical vias electrically vertically connect traces or paths of thedifferent patterned metal layers of the metallization structure and thepatterned top metal layer disposed on the IMD. A final packaging stepentails performing ball bonding, wire bonding, or the like to wirecontact pads of the BEOL metallization structure to electrical power,signal ports, or the like, along with other possible processes such asmounting the IC, encapsulating the IC, or so forth, so as to install theIC into a functioning electronic device, system, or so forth.

The contact pads of the BEOL may serve as wire bonding pads or flip-chipbonding pads. In these contacting schemes, a bonding ball of solder oranother material is deposited onto the contact pads to low electricalresistance contact. Some contact pads may also serve as probe pads forneedle probes or the like of IC testing equipment. The contact padshould therefore be robust against electrical contacting methods such aswire bonding or contacting with a needle probe. In ICs with smallfeature size, a big via which is many times larger than a regular viacan be used to provide support for a metal pad.

The metallization structure also may include resistors formed in apatterned layer of a high resistivity (HiR) material embedded in the IMDlayer, such as titanium nitride (TiN), tantalum nitride (TaN), or thelike; as well as capacitors. These components can be used for variouspurposes, such as forming RC circuits for tuning of microwave signals,providing charge/discharge capacitors for capacitive charge pumps ofBiCMOS circuitry, providing decoupling capacitors, and so forth. TheBEOL capacitor is typically embedded in the IMD layer and comprises ametal-insulator-metal (MIM) capacitor defined by two metal layers spacedapart by a thin insulator layer. One of the patterned metal layers ofthe metallization structure which is used for IC electrical interconnecttraces or paths can also serve as a bottom metal layer of the MIMcapacitor. However, the top metal layer is an extra layer used only forthe BEOL MIM capacitors.

In embodiments disclosed herein, improved BEOL MIM capacitor devices andcorresponding methods of manufacture are disclosed. These approachesintegrate the MIM capacitor fabrication into the fabrication of the bigvia and other vias connecting with the top metal layer. The disclosedfabrication approaches reduce process cost and improve process cycletime.

With reference to FIG. 1 , a cross-sectional view is diagrammaticallyshown of an integrated circuit (IC) 10. The IC 10 includes a FEOL devicestructure 12 comprising transistors, charge storage devices, and othercircuit components fabricated on a semiconductor wafer. For example, ifthe IC 10 is a silicon-based IC, then the device structure 12 mayinclude a silicon wafer on which is fabricated various types of fieldeffect transistors (FETs) such as planar FETs, finFETs, gate-all-around(GAA) FETs, and/or so forth; charge storage devices such ascharge-coupled devices (CCDs) or FET-based charge storage devices, MIMcapacitors, and/or so forth. Depending on the purpose of the IC 10, thecircuit components of the device structure 12 may additionally includeoptoelectronic devices such as photodiodes, phototransistors, and/or soforth. The device structure also may include shallow trench isolation(STI) regions, n-type and/or p-type doped layers, and so forth.

The IC 10 further includes a BEOL metallization structure 14 thatincludes an intermetal dielectric (IMD) layer 20, and at least onepatterned metal layer 22 is embedded in the IMD layer. While a singleembedded patterned metal layer 22 is shown, it will be appreciated thatthere may be multiple patterned metal layers in the metallizationstructure. A top patterned metal layer 24 is disposed on the IMD layer20.

For convenience in the description of the metallization structure 14,vertical and lateral directions may be referred to herein, as well ascomparative upper and lower descriptive terms such as above, below,beneath, top, bottom, or so forth. These descriptive terms arereferenced to the plane of the substrate of the IC 10, such as thesilicon wafer (or a transfer substrate in a case in which the electronicdevice layers are transferred from the growth silicon substrate to adifferent host substrate during a wafer transfer process performed inthe FEOL). The vertical direction V labeled in FIG. 1 is perpendicularto the wafer of the IC 10. An upper element or component of themetallization structure 14 is more distant from the device structure 12along the vertical direction V as compared with a lower element orcomponent of the metallization structure 14 which is closer to thedevice structure 12 along the vertical direction V. The patterned topmetal layer 24 is therefore the uppermost element or component of themetallization structure 14, as it is furthest away from the devicestructure 12. Similarly, the at least one patterned metal layer 22 isbeneath the top patterned metal layer 24. The indicated lateraldirection(s) L refers to any direction that is transverse to thevertical direction V, i.e. a lateral direction is parallel with theprincipal surface of the wafer on which the components of the devicestructure 12 are fabricated.

The at least one buried patterned metal layer 22 and the top patternedmetal layer 24 are patterned in the lateral directions to defineelectrical traces interconnecting components of the device structure 12,for providing landing pads for contacts, or other electricalinterconnect features. While a single buried metal layer 22 is shown forillustrative purposes, in a complex IC there may be several buried metallayers embedded in the IMD layer 20 at different vertical levels, i.e.multiple metallization layers. Electrical vias 26 pass through the IMDlayer 20 and connect the patterned top metal layer 24 and the patternedmetal layer 22 embedded in the IMD layer 20. If there are multipleembedded layers in the IMD layer 20 then similar electrical vias (notshown) suitably connect the various metallization layers. Furtherelectrical vias (not shown) also connect the lowermost embedded metallayer with the device structure 12.

The IMD layer 20 is suitably made of an IMD material which is a suitabledielectric material. For example, the IMD material can be un-dopedsilicate glass (USG), silicon dioxide (SiO₂), SiOCN, SiOCH, variouscombinations thereof, and/or so forth. Furthermore, typically the buriedand top patterned metal layers 22, 24 are made of a metal layermaterial, and the vias 26 are made of a via material that is differentfrom the metal layer material. For example, the metal layer material maybe aluminum, copper, or an alloy of aluminum and copper, and the viamaterial may be tungsten. This is merely an illustrative example, andmore generally the metal layer material can be aluminum, copper,tungsten, cobalt, ruthenium, various alloys or multilayers thereof, orso forth. Similarly, more generally the via material may be tungsten,zinc, gold, nickel, various alloys thereof, or so forth. Still further,in some embodiments of the buried and top metal layers 22, 24 mayinclude titanium nitride (TiN) or other cladding 25 of the metal layermaterial (e.g. AlCu). Other types of cladding material are alsocontemplated, such as tantalum nitride (TaN) or another metal nitridealloy cladding. As yet a further variant, the top patterned metal layer24 and each of the one or more buried patterned metal layers 22 may havedifferent material constitution.

In the example of FIG. 1 , one illustrated via of the electrical vias isa “big” via 26B. The big via 26B is substantially larger than otherillustrated electrical vias, and contacts a large area of the patternedtop metal layer 24 which defines a contact pad 28. Hence, the big via26B is also referred to herein as a contact pad via 26B. The contact pad28 is of sufficiently large area to facilitate bonding during packagingof the IC 10. For example, FIG. 1 diagrammatically shows a bonding ball29 disposed on the contact pad 28 for use in wire bonding (as shown) orflip-chip bonding, or the like. In other embodiments, the contact pad 28may be used as a landing site for a probe of an electrical testingdevice, such as an oscilloscope probe, voltmeter probe, or so forth. Acontact pad landing area 22B of the patterned metal layer 22 embedded inthe IMD layer is arranged underneath the contact pad 28. The contact padlanding area 22B, big via 26B, and contact pad 28 typically havecomparable lateral areas. In some illustrative embodiments, the big via36B has a largest lateral dimension of at least 30 microns, and in therange 30-200 microns in some embodiments. By contrast, the other (i.e.non-big) vias 26 may in some embodiments have a largest lateraldimension of 0.1 micron, and a largest lateral dimension in the range0.1 to 0.5 micron in some embodiments. In some embodiments, the big via26B has a largest lateral dimension that is at least 50 times largerthan a largest lateral dimension of the small (i.e. non-big) vias of theplurality of small vias 26. The illustrative contact pad via 26B has abottom and a sidewall. It should also be noted that while FIG. 1illustrates a single contact pad 28 with a single underlying big via 28and further underlying contact pad landing area 22B of the embeddedpatterned metal layer 22, the IC 10 may in general include one, two,three, or more contact pads with corresponding underlying big vias andcontact pad landing areas. The different contact pads may provide forelectrical contact during packaging to different parts of the IC, suchas electrical contact of V_(CC) and ground terminals and various signalinputs and outputs.

In a typical IC fabrication process, the device structure 12 ismanufactured in front end-of-line (FEOL) processing, followed bymetallization performed during back end-of-line (BEOL) processing whichforms the metallization structure 14. However, this division ofprocessing is not necessarily strictly followed in a given ICfabrication process. For example, the FEOL processing may includeforming some electrical interconnects between components of the devicestructure 12. Similarly, there may be devices formed in the BEOLprocessing, such as an illustrative metal-insulator-metal (MIM)capacitor 30 formed during the BEOL processing as a component of themetallization structure 14. Consequently, the MIM capacitor 30 is alsoreferred to herein as a BEOL capacitor 30, or as a BEOL MIM capacitor30.

As diagrammatically shown in FIG. 1 , the MIM capacitor 30 includes abottom capacitor metal 32, an insulator layer 34, and a top capacitormetal 36. The insulator layer 34 suitably comprises a thin layer ofsilicon oxide, silicon nitride, silicon glass, a high dielectricconstant (high-k) material such as tantalum oxide (e.g. TaO₂ or Ta₂O₅),hafnium oxide (HfO₂), aluminum oxide (e.g., Al₂O₃), zirconium oxide(e.g., ZrO₂), yttrium oxide (e.g., Y₂O₃), multilayer structures of suchmaterials, or so forth.

In embodiments disclosed herein, the bottom capacitor metal 32 and thetop capacitor metal 36 both comprise the via material—that is, thebottom capacitor metal 32 and the top capacitor metal 36 both comprisethe same material as the vias 26. For example, in some embodiments, thebottom capacitor metal 32 and the top capacitor metal 36 both comprisetungsten, as do the vias 26 (including the big via 26B) in this specificembodiment. As seen in FIG. 1 , the bottom capacitor metal 32 connectswith an area 22C of the patterned metal layer 22 that is embedded in theIMD layer 20. Hence, this area 22C is also referred to herein as an MIMcapacitor landing area 22C of the patterned metal layer 22 embedded inthe IMD layer 20. The top capacitor metal 36 connects with an area 24Cof the top patterned metal layer 24. Hence, this area 24C is alsoreferred to herein as a first MIM capacitor terminal area 24C of thepatterned top metal layer 24.

Because the top and bottom capacitor metals 32, 36 comprise the viamaterial, the MIM capacitor 30 can be considered to comprise a via 32,36 (also referred to herein as first via 32, 36) with the dielectriclayer 34 embedded in the first via 32, 36. The insulator layer 34 of theMIM capacitor 30 thus divides the first via 32, 36 into: (i) a viaportion 32 galvanically contacting the MIM capacitor landing area 22C ofthe patterned metal layer 22 embedded in the IMD layer 20; an (ii) a viaportion 36 galvanically contacting the first MIM capacitor terminal area24C of the patterned top metal layer 22. To provide a second terminalfor electrically contacting the capacitor 30, a second via 26C of theelectrical vias 26 connects the MIM capacitor landing area 22C of thepatterned metal layer 22 embedded in the IMD layer 20 with a second MIMcapacitor terminal area 24D of the patterned top metal layer 24. Hence,the capacitance of the MIM capacitor 30 is presence across the terminals24C, 24D.

With reference to FIG. 2 , an isolation cross-sectional view of the MIMcapacitor 30 is diagrammatically shown, with the bottom capacitor metal32, insulating layer 34, and top capacitor metal 36 again shown. As canbe seen in FIGS. 1 and 2 , each of these layers 32, 34, 36 has a bottomand sidewall, and the sidewall has lateral dimension D and F indicatedin FIG. 2 . In general, the lateral dimension D is greater than zero andthe lateral dimension F is greater than zero (i.e., the sidewall hasfinite lateral width). In some embodiments, D=F, although this is notnecessary. The top metal layer 36 defines an inner volume of verticaldimension x and of lateral dimension E, which is filled with adielectric material 40 that is typically (although not necessarily) thesame material as the IMD material of the IMD layer 20. The top capacitormetal 36 also includes a connecting portion 42 in the inner volume ofdimension E, again made of the same via material as the electrical vias26 (including the big via 26B) and the bulk of the top capacitor metal36. The connecting portion 42 passes through the dielectric material 40and electrically connects the bulk of the top capacitor metal 36 to thefirst MIM capacitor terminal area 24C of the patterned top metal layer24 (see FIG. 1 ).

With reference to FIGS. 3-14 , an illustrative approach for fabricatinga metallization structure such as (by way of non-limiting illustrativeexample) the metallization structure 14 of FIG. 1 is described. FIG. 3shows the fabrication process by way of a flowchart. FIGS. 4-14diagrammatically show cross-sectional views of the BEOL metallizationstructure under fabrication at various steps of the BEOL fabricationprocess of FIG. 3 . FIGS. 4-14 depict the fabrication of the structureof FIGS. 1 and 2 ; however, it will be appreciated that the BEOLprocessing of FIG. 3 is not limited to fabrication of that metallizationstructure 14.

In an operation 50 of FIG. 3 and with further reference to FIG. 4 , theIMD layer 20 is formed with the patterned metal layer 22 embedded in theIMD layer 20. This fabrication operation can be done in various ways. Ina typical approach, the portion of the IMD layer 20 beneath thepatterned metal layer 22 is first deposited, followed by deposition of acontinuous metal layer that is then lithographically patterned to formthe patterned metal layer 22. If the metallization structure includestwo (or more) buried patterned metal layers, this process may berepeated for each additional buried patterned metal layer. Finally, theportion of the IMD layer 20 above the topmost buried patterned metallayer 22 is deposited to bury that topmost layer and thus form thestructure diagrammatically shown by cross-section in FIG. 4 .

In an operation 52 of FIG. 3 and with further reference to FIG. 5 , theformation of the BEOL capacitor 30 begins by etching the IMD layer toaccess the MIM capacitor landing area 22C. As seen in FIG. 5 , thisresults in an opening 70 being formed in the IMD layer 20 that exposesthe upper surface of the MIM capacitor landing area 22C. The operation52 suitably employs photoresist patterning to define an opening in theresist corresponding to the opening 70 followed by etching the IMD layer20 in that photoresist opening. The etching can employ any type ofetching process that selectively etches the IMD material over the metalof the buried patterned metal layer 22. Advantageously, the MIMcapacitor landing area 22C serves as a suitable etch stop.

In an operation 54 of FIG. 3 and with further reference to FIG. 6 , afirst layer of via material 32L is deposited. In the illustrativeexample as seen in FIG. 6 , the operation 54 deposits the first layer32L on the portion of the MIM capacitor landing area 22C exposed by theopening 70, and also deposits the first layer 32L outside of the exposedportion of the MIM capacitor landing area 22C, that is, on the portionof the IMD layer 20 that was not removed in the operation 54. Thisexcess deposition will be removed later in the process so as to leaveonly the bottom capacitor metal 32—the distinction is indicated in FIG.6 by use of the label 32L to indicate the deposited layer. Thedeposition operation 54 may use any deposition technique suitable fordepositing the via material. For example, the deposition may be byvacuum evaporation, sputter deposition, electroplating, physical vapordeposition (PVD), chemical vapor deposition (CVD), atomic layerdeposition (ALD), or so forth.

In an operation 56 of FIG. 3 and with further reference to FIG. 7 , aninsulator layer 34L is deposited on top of the first layer 32L. Again,the label 34L indicates the entire deposited layer, most of which willlater be removed so as to leave only the insulating layer 34 of the MIMcapacitor 30. The deposition operation 56 may use any depositiontechnique suitable for depositing the silicon oxide, silicon nitride,silicon glass, high-k material such as TaO₂, Ta₂O₅, HfO₂, Al₂O₃, ZrO₂,Y₂O₃, or other insulating material that will make up the insulatinglayer 34 of the MIM capacitor 30. For example, the deposition may be byvacuum evaporation, sputter deposition, electroplating, PVD, CVD, ALD,or so forth.

In an operation 58 of FIG. 3 and with further reference to FIG. 8 , asecond layer of via material 36L is deposited on the insulating layer34L. Again, the label 36L indicates the entire deposited layer, most ofwhich will later be removed so as to leave only the top capacitor metal36 of the MIM capacitor 30. The deposition operation 58 may again useany deposition technique suitable for depositing the via material, suchas vacuum evaporation, sputter deposition, electroplating, PVD, CVD,ALD, or so forth.

In an operation 60 of FIG. 3 and with further reference to FIG. 9 ,additional IMD material 20 ₁ is deposited to at least a thickness xcorresponding to the remainder of the opening 70 (see FIG. 5 ) that wasnot filled in by the deposition operations 54, 56, 58. Comparison withFIG. 2 shows that the thickness x shown in FIG. 9 is the same as thethickness x of FIG. 2 . As further seen in FIG. 9 , the thickness towhich the additional IMD material 20 ₁ is deposited can optionallyexceed the thickness x, which is merely a minimum thickness. Thedeposition operation 60 may use any deposition technique suitable fordepositing the USG, silicon dioxide, SiOCN, SiOCH, or other IMDmaterial. For example, the deposition may be by vacuum evaporation,sputter deposition, electroplating, PVD, CVD, ALD, or so forth.

Notably, the top surface of the additional IMD material 20 ₁ is notexpected to be perfectly planar, because a surface pit or depression 72is likely to be present due to the IMD material that fills the remainderof the opening 70.

Accordingly, a planarization operation 62 is performed to planarize thesurface. The planarization operation 62 may, for example, employgrinding or chemical mechanical polishing (CMP) to remove the additionalIMD material 20 ₁ down to the level of the top of the second layer 36L,as diagrammatically shown in FIG. 10 . This leaves IMD material disposedonly in a recess of the second layer of via material 36L. With referenceto FIG. 11 , a further CMP step, or further grinding, removes the viamaterial of the first and second layers 32L, 36L of via material alongwith the thin insulator layer 34L therebetween except where those layers32L, 34L, 36L coat the opening 70 formed in the operation 52 (see FIG. 5). This leaves the bottom capacitor metal 32, the insulator layer 34,and the top capacitor metal 36 of the capacitor 30, along with thedielectric material 40, as shown in FIG. 11 . The further CMP forremoving the via material may use a different etchant chemical than theCMP that removed the additional IMD material. Alternatively, both may beremoved in a single continuous grinding or CMP operation. Theplanarization operation 62 may be timed based on calibration runs toprovide the planarization to the desired depth, i.e. stopping at thesecond layer of via material 36L, or may be monitored using opticalreflectometry or the like to ensure the planarization stops at the pointwhen the first layer 32L has been fully removed outside of the opening70.

In an operation 64 of FIG. 3 and with further reference to FIG. 12 ,formation of the electrical vias 26 is next performed. This entailsphotolithographically patterned etching to form the openings for thevias 26 (including a relatively large opening for the big via 26B, andalso an opening for the connecting portion 42 of the top capacitor metal36, cf. FIG. 2 ), and subsequent deposition of the via material intothose openings (optionally using the same patterned photoresist as usedfor the etching), followed by optional CMP to planarize the surface. Theoperation 64 can suitably employ any electrical via fabrication processused in BEOL processing. In the illustrative embodiment, the contact padvia 26B has a bottom and a sidewall due to the large area of the openingthat is coated with the via material during the operation 64.

In an operation 66 of FIG. 3 and with further reference to FIG. 13 , atop metal layer 24L is deposited. The label 24L is used to distinguishthe continuous top metal layer 24L from the patterned top metal layer 24to be formed by patterning in the next step. The deposition operation 66may use any deposition technique suitable for depositing the metal layermaterial (e.g., aluminum, copper, or an alloy of aluminum and copper, invarious illustrative embodiments) of the top metal layer 24L. Forexample, the deposition may be by vacuum evaporation, sputterdeposition, electroplating, physical vapor deposition (PVD), chemicalvapor deposition (CVD), atomic layer deposition (ALD), or so forth.Moreover, in the illustrative example of FIG. 13 , the depositionoperation 66 includes depositing a lower cladding layer 25L1 prior todepositing the metal layer material, and depositing an upper claddinglayer 25L2 after depositing the metal layer material. Again, the labels25L1 and 25L2 for the continuous cladding layers 25L1 and 25L2 are useddifferentiate these continuous cladding layers from the patternedcladding layers 25 of the patterned top metal layer 24.

In an operation 68 of FIG. 3 and with further reference to FIG. 14 , thecontinuous top metal layer 24L is lithographically patterned to form thepatterned top metal layer 24, including the previously described contactpad 28 and the first and second terminals 24C, 24D of the capacitor 30.This completes the BEOL processing of FIG. 3 and produces themetallization structure 14 as shown in FIG. 14 .

In the illustrative example of FIGS. 3-14 , a single BEOL capacitor 30is fabricated. However, more generally the BEOL processing of FIG. 3 maybe used to concurrently fabricate any number of BEOL capacitors. To doso, in the operation 50 the buried patterned metal layer 22 is suitablypatterned to define an MIM capacitor landing area 22C for each BEOLcapacitor to be fabricated. In the operation 52, the photomask used todefine the lithographic pattern for the accessing MIM capacitor landingareas defines an opening 70 (see FIG. 5 ) at the location of, and sizedto correspond to, each respective MIM capacitor landing area 22C. Thefollowing operations 54, 56, 58, and 60 performing blanket deposition oflayers and the planarization 62 can be performed over the entire wafer,or over at least an area of the wafer encompassing all locations whereBEOL capacitors are to be formed, and hence these operations are notmodified in the case of fabricating multiple BEOL capacitors. In theoperation 64, the via formation includes forming the connecting portion42 of the top capacitor metal 36 for each respective capacitor, whichagain merely entails appropriate modification of the photomask used inthe via formation operation 64. The subsequent blanket top metal layerdeposition operation 66 is again not modified, and the final top metallayer patterning operation 68 again entails modifying the photomask usedin this operation to define the first and second terminals 24C and 24Dfor each respective BEOL capacitor.

Similarly, while the illustrative examples of FIGS. 3-14 forms a singleillustrative contact pad 28 with underlying big via 26B and contact padlanding area 22B of the buried patterned metal layer 22, this can bereadily modified to fabricate multiple contact pads by appropriatemodification of the photomasks used to pattern the buried patternedmetal layer 22, the via formation, and the top metal layer patterning.

In the following, some additional illustrative embodiments aredisclosed.

In some illustrative embodiments, an integrated circuit includes adevice structure comprising circuit components, and a metallizationstructure disposed on the device structure and providing electricalinterconnects for the circuit components of the device structure. Themetallization structure includes an intermetal dielectric (IMD) layer, apatterned metal layer embedded in the IMD layer, a patterned top metallayer disposed on the IMD layer, electrical vias passing through the IMDlayer and connecting the patterned top metal layer and the patternedmetal layer embedded in the IMD layer, and a metal-insulator-metal (MIM)capacitor. The MIM capacitor includes a first via of the electrical viasand an insulator layer embedded in the first via.

In some illustrative embodiments, a method of manufacturing ametallization structure of an integrated circuit (IC) is disclosed. Anintermetal dielectric (IMD) layer is formed, comprising IMD materialwith a patterned metal layer embedded in the IMD layer. Ametal-insulator-metal (MIM) capacitor is formed by operations including:etching the IMD to access an MIM capacitor landing area of the patternedmetal layer embedded in the IMD layer, depositing a first layer of viamaterial on the MIM capacitor landing area, depositing an insulatorlayer on the first layer of via material, and depositing a second layerof via material on the insulator layer. Vias are formed, comprising thevia material. The formed vias include a first MIM capacitor viacontacting the second layer of via material and a second MIM capacitorvia contacting the MIM capacitor landing area and an IC contact pad via.A top metal layer is deposited and patterned to define first and secondMIM capacitor terminals disposed on the respective first and second MIMcapacitor vias and an IC contact pad disposed on the IC contact pad via.

In some illustrative embodiments, a metallization structure of anintegrated circuit (IC) includes: an intermetal dielectric (IMD) layer;a patterned metal layer embedded in the IMD layer; a patterned top metallayer disposed on the IMD layer; electrical vias comprising via materialpassing through the IMD layer and connecting the patterned top metallayer and the patterned metal layer embedded in the IMD layer; and ametal-insulator-metal (MIM) capacitor. The MIM capacitor includes: afirst capacitor metal layer comprising the via material contacting anMIM capacitor landing area of the patterned metal layer embedded in theIMD layer; a second capacitor metal layer comprising the via materialcontacting a first MIM capacitor terminal area of the patterned topmetal layer; and an insulator layer disposed between the first capacitormetal layer and the second capacitor metal layer.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. An integrated circuit comprising; a devicestructure comprising circuit components; and a metallization structuredisposed on the device structure and providing electrical interconnectsfor the circuit components of the device structure, the metallizationstructure including: an intermetal dielectric (IMD) layer, a patternedmetal layer embedded in the IMD layer, a patterned top metal layerdisposed on the IMD layer, electrical vias passing through the IMD layerand connecting the patterned top metal layer and the patterned metallayer embedded in the IMD layer, and a metal-insulator-metal (MIM)capacitor including a first via of the electrical vias and an insulatorlayer embedded in the first via.
 2. The integrated circuit of claim 1wherein the insulator layer of the MIM capacitor divides the first viainto: a via portion galvanically contacting an MIM capacitor landingarea of the patterned metal layer embedded in the IMD layer; and a viaportion galvanically contacting a first MIM capacitor terminal area ofthe patterned top metal layer.
 3. The integrated circuit of claim 2wherein the MIM capacitor further includes a second via of theelectrical vias which connects the MIM capacitor landing area of thepatterned metal layer embedded in the IMD layer and a second MIMcapacitor terminal area of the patterned top metal layer.
 4. Theintegrated circuit of claim 1 wherein the insulator layer of the MIMcapacitor is spaced apart from the patterned metal layer embedded in theIMD layer by a first portion of the first via and is spaced apart fromthe patterned top metal layer by a second portion of the first via. 5.The integrated circuit of claim 4 wherein the electrical vias comprise avia material and the patterned metal layer embedded in the IMD layercomprises a metal layer material and the patterned top metal layercomprises the metal layer material, and the via material is differentfrom the metal layer material.
 6. The integrated circuit of claim 5wherein the via material comprises tungsten or a tungsten alloy.
 7. Theintegrated circuit of claim 6 wherein the metal layer material comprisesaluminum, copper, or an alloy of aluminum and copper.
 8. The integratedcircuit of claim 7 wherein: the patterned metal layer embedded in theIMD layer further comprises titanium nitride (TiN) cladding the metallayer material of the patterned metal layer embedded in the IMD layer;and and the patterned top metal layer further comprises TiN cladding themetal layer material of the patterned top metal layer.
 9. The integratedcircuit of claim 1 further comprising: a contact pad of thesemiconductor device comprising a contiguous area of the patterned topmetal layer; a contact pad landing area of the patterned metal layerembedded in the IMD layer arranged underneath the contact pad; and acontact pad via interposed between and electrically connecting thecontact pad and the contact pad landing area of the patterned metallayer embedded in the IMD layer.
 10. The integrated circuit of claim 9wherein the contact pad has a lateral dimension of at least 30 micronsand the contact pad via has a lateral dimension of at least 30 micronsand the contact pad landing area has a lateral dimension of at least 30microns.
 11. The integrated circuit of claim 9 wherein the contact padvia has a bottom and a sidewall.
 12. The integrated circuit of claim 1wherein: the electrical vias include a big via and a plurality of smallvias; the big via has a largest lateral dimension that is at least 50times larger than a largest lateral dimension of the small vias of theplurality of small vias.
 13. A method of manufacturing a metallizationstructure of an integrated circuit (IC), the method comprising; formingan intermetal dielectric (IMD) layer comprising IMD material with apatterned metal layer embedded in the IMD layer; forming ametal-insulator-metal (MIM) capacitor by operations including: etchingthe IMD to access an MIM capacitor landing area of the patterned metallayer embedded in the IMD layer, depositing a first layer of viamaterial on the MIM capacitor landing area, depositing an insulatorlayer on the first layer of via material, and depositing a second layerof via material on the insulator layer; forming vias comprising the viamaterial including a first MIM capacitor via contacting the second layerof via material and a second MIM capacitor via contacting the MIMcapacitor landing area, and an IC contact pad via; and depositing andpatterning a top metal layer to define first and second MIM capacitorterminals disposed on the respective first and second MIM capacitor viasand an IC contact pad disposed on the IC contact pad via.
 14. The methodof claim 13 wherein the depositing of the first and second layers of viamaterial also deposit via material outside of the MIM capacitor landingarea, and the forming of the MIM capacitor further includes chemicalmechanical polishing (CMP) to remove the via material deposited outsideof the MIM capacitor landing area.
 15. The method of claim 14 whereinthe forming of the MIM capacitor further includes: depositing IMDmaterial on the second layer of via material; wherein the CMP alsoremoves the IMD material deposited on the second layer of via materialoutside of the MIM capacitor landing area.
 16. The method of claim 14wherein the patterned metal layer embedded in the IMD layer comprises ametal layer material and the via material is different from the metallayer material.
 17. The method of claim 14 wherein: the patterned metallayer embedded in the IMD layer comprises aluminum, copper, or an alloyof aluminum and copper; and a the via material comprises tungsten or atungsten alloy.
 18. A metallization structure of an integrated circuit(IC), the metallization structure comprising: an intermetal dielectric(IMD) layer; a patterned metal layer embedded in the IMD layer; apatterned top metal layer disposed on the IMD layer; electrical viascomprising via material passing through the IMD layer and connecting thepatterned top metal layer and the patterned metal layer embedded in theIMD layer; and a metal-insulator-metal (MIM) capacitor including: afirst capacitor metal layer comprising the via material contacting anMIM capacitor landing area of the patterned metal layer embedded in theIMD layer, a second capacitor metal layer comprising the via materialcontacting a first MIM capacitor terminal area of the patterned topmetal layer, and an insulator layer disposed between the first capacitormetal layer and the second capacitor metal layer.
 19. The metallizationstructure of claim 18 wherein: the patterned metal layer embedded in theIMD layer comprises a metal layer material; the patterned top metallayer comprises the metal layer material; and the metal layer materialis different from the via material.
 20. The metallization structure ofclaim 19 wherein: the patterned metal layer embedded in the IMD layerfurther comprises a metal nitride alloy cladding the metal layermaterial of the patterned metal layer embedded in the IMD layer; and andthe patterned top metal layer further comprises the metal nitride alloycladding the metal layer material of the patterned top metal layer.